The next day, the Shane gang are fighting Blank enforcers but they were pin down while finding cover and firing back.

Eli: They seem angry.

Trixie: Like they really want to hurt us.

YN: Don't they always want to hurt us?

Pronto: It must have been something I said. This happens from time to time.

YN: Either way, we gotta clear them out.

Trixie: Leave that to us.

Trixie and Kord fired a digger slug n a armashell, successfully attacking from underneath.

Eli: How's it looking out there?

Kord: Let me check. Cover me!

They did as he said while he pulls out a binocular to spot a grenuke slug landed near the goons before exploding.

Kord: (Smirk.) I love Grenuke slugs.

Once the cloud of dust was gone, Kord spotted Blakk is leading the reinforcement.

Kord: Oh man, here comes Dr Blakk.

Kord tosses the binocular to Eli to check. Soon they all charge in to where the Shane gang.

Kord: Here they come!

Trixie: I don't see any way out!

YN: They got us cornered!

Pronto: Then Pronto will fight to his last slug.

He pulls out his last slug which unfortunately its a flopper.

Pronto: Unfortunately that would be him.

Trixie: Eli, they're trying to push us backwards towards that!

Trixie points at the bottomless cliff.

YN: The great abyss.

Eli: Dr Blakk thinks he's got this game all figured out. Well we're gonna bend the rules a little. YN, give us come cover!

YN: On it. Pronto, got a stink slug?

Pronto: Aha! There he is.

Pronto fires a stink slug after YN fired Twist slug to hold Blakk and his goons off for as long as it can. With it, it gave the Shane gang enough time to escape with their mechas and head straight towards the cliff.

Trixie: Eli, this goes to the gorge, its a dead end!

Eli: Blakk wants us in that gorge? Let's give him exactly what he wants!

YN: It is better to die as a free man than to live as a prisoner man!

With that, they jump down to the cliff while screaming except for YN.

YN: Yeeeeehaaaaaaw!

Trixie: Next time you guys feel like bending the rules like this, don't!

Kord: We'll be fine, just have to deploy our newest upgrade. Pull the red doohickey now!

They immediately do exactly what he said and their mechas turns to flight mode as they're close to the ground.

Eli: Okay, get ready to land!

YN: Brace yourselves!

They landed safely though Pronto crash. Luckily Kord catches him on time.

Pronto: I'm fine, I'm fine, let go of me! You act as though I'm a bumbling fool! (Slips and falls.) Well don't just stand there, help me up!

YN: (Whispers.) So much for bambling fool.

Eli helps him up while the rest hop off their mechas until Eli spotted something familiar.

Eli: Guys, check it out.

They look to where Eli is pointing and see some kind of chair.

They take a closer look to see its very old.

Kord: That's not something I expected to find here.

Trixie: What do you think it is?

Eli: I've seen one of these before, it looks just like the drop.

YN: Like the one you used?

Eli: (Nods.) If the Shanes could build an elevator from the surface to slugterra, they can also build one from slugterra to down here.

Kord: Why would a Shane want to come here?

YN: I'll bet the drop went off course and ended up here. But why and how?

Pronto: I am so glad you asked for Pronto had devised a most convincing theory. You see-

Eli: Pronto! Shh!

They became silent only to hear something rumbling and they follow to where its coming from until YN spotted something.

YN: Its coming from there.

They saw something was glowing for the moment.

Kord: What do you think it is?

Eli: No idea.

Suddenly all their slugs became excited like they're waiting for something amazing to happened.

Eli: Whatever it is, they're eager to get down there. Come on!

They head down there and find the stairs. As they're heading down, all their slug jump out of the tubes including from the blaster and all ran down.

Eli: Hey, Where you guys going?

YN: Frost?

Frost ignores him as well as Burpy ignoring Eli.

YN: That's odd, Frost never done that before.

Eli: Its definitely something.

Kord: Where are we?

They arrive to a small cavern where there's a slug in each spot and each have a glowing symbol above their head.

Trixie: Those are slugs.

YN: Incredible, every single one from different types of slugs.

Eli: Something different about them.

Suddenly the cavern shakes again and they see some kind if large gate.

Kord: All I know is that's one heck of a forcefield. I don't think I want to know what it's holding back.

Trixie then spots a shadow clan.

Trixie: Eli, a shadow clan.

The shadow clan approaches towards the gang.

YN: I'm guessing this guy knows what.

Eli: Everyone stay calm. Don't make any sudden moves. (To shadow clan.) I'm just gonna out this on so I can understand you while my friend can listen to you too. Okay?

Eli puts it on and it gave him a little headache while YN tries to concentrate to understand what he saying.

Shadow: Who are you? How have you come to possess the shadow talker and how can your friend understand? Answer!

Eli: I'm Eli Shane, it belong to my father.

YN: And I'm YN LN.

His eyes widen to met another LN but was cut short as the cavern shakes again before Eli ask curiously.

Eli: What is this place?

Shadow: The very edge of slugterra. You have arrive at the crossing and just in time.

YN: Crossing? To where?

Shadow: The Deep Caverns...home of the Darkbane.

YN: Darkbane? I feel like I've heard that before...

Shadow: Our guardian slugs help keep their armies at bay.

Eli: Guardian slugs?

Shadow: The most powerful slugs of all.

Meanwhile with the rest of the gang are having trouble to understand their conversation.

Eli: He says the constant attacks on the force wall is sapping their strength.

YN: More guardians are on the way, but he's not sure how long they can keep this up. It could fall at any moment before we know it.

Eli: Can our slugs help?

Shadow: You have powerful slugs indeed. Very impressive, but they're not ready to be guardians yet.

YN: What about Frost? She's rare and powerful slug.

Shadow: Very rare and powerful indeed. But it is not her place to become a guardian.

YN: Oh...

Eli: Then we're just gonna have to find a way to stop whatever's doing this until the cavalry arrives.

Shadow: I know of no other way to reinforce the wall.

Eli: I'm not talking about reinforcing the wall. We have to fight back.

Shadow: You would risk your lives for this?

YN: Slugterra is our home, no way we're backing out while letting something bad barging here.

Eli: Besides, we're the Shane gang. That's what we do.

Shadow: We cannot risk opening the passage, but this shadow walker will transport you inside.

The shadow clan continue to speak before Eli talks.

Eli: Do you want the good news or the bad news?

Trixie: Its a one way trip, isn't it?

YN: Yup.

Eli: He says this won't work once we're inside.

Kord: What's the good news?

YN: Oh you know, saving slugterra from unspeakable evil. According to him, if the Darkbane armies breaks through, there's no stopping them.

Kord: Well then, what are we waiting for?

Shadow: Move quickly and go.

All their slugs hop back on to the tubes before the Shane gang place their hands on the shadow walker until YN ask the shadow out of curiosity.

YN: Is there anything else we need to know?

Shadow: (Nods.) Though it may be the dark caverns. You may find help from the other side.

YN: Help? Who would help us-

He was then cut off as they teleported away which got YN upset before facing Eli.

YN: Hey! I was gonna ask who would help us!

Eli: Uh, I don't think we might find help, look.

YN sees that they arrive to the other side of the gate. Where as the shadow mentioned, it took them to the deep caverns.

Kord: Welcome to the deep caverns people.

Suddenly they hear something roar close and sees a giant monster.

Kord: (Nervous.) That must be the Darkbane.

It charges straight towards them and they quickly got out of the way. However, the creature was hitting the gate instead of them.

Trixie: We're supposed to stop this thing?

YN: Not like we have a choice. That thing is the one trying to destroy it.

Eli: Start slinging on my mark.

The Shane gang aims at the creature until Eli signals them to fire. However, the slugs didn't transformed as all the slugs hit but the creature didn't even flinch.

Eli: What's wrong with our slugs!? They didn't transformed!

YN: Not even the fusion slugs do anything!

Trixie: The dark energy here must be canceling out their powers!

???: Midlanders!

They look to see the Darkbanes approaching towards them.

Darkbane: Surrender or face oblivion!

YN: Slugs or not. (Cracks his knuckles.) I can still hit them!

Suddenly the large Darkbane throws a orb of lava near them.

Trixie: These guys throw lavas.

YN: On second thought, running would be a good idea for all of us right?

Shane gang: Yeah...

The Shane gang made a run while the Darkbanes fire more orbs of lava at them. YN quickly ducks in cover from the lava being thrown. After that, he charges at them while evading the lava. As soon as he got close, he goes for a dropkick at one with a spear.

Successfully knocking one down before the other went to attack him. However, YN quickly turn around and hit him with a knee directly towards his face.

YN: Two down, one to go.

Darkbane: Impressive, very few can take on a Darkbane. Especially with that strength. But fighting us will be your biggest mistake of your life.

YN: Then call off your behemoth and beat it. Before I put you down like your friends here.

Darkbane: You have spirit, but you won't last longer.

YN get in his fighting stance, ready to face the Darkbane as it goes for the punch. YN immediately dodged it and goes for the uppercut punch. It was successful at first but the Darkbane just shakes it off before going for another brute punch as YN once again dodges it and went for another punch.

The Darkbane backs away from the hit before YN goes for the final blow. However, it was reckless as the Darkbane catches it and swings him and throws him directly towards the wall.

Meanwhile the Shane gang continues to run until they were cut off by the dark water blocking their path.

Eli: Dark water!

Just then the Darkbane arrives with YN as a hostage.

Darkbane: You will come with us, or you will watch your friend dies.

YN: Guys don't-

He was cut off as the Darkbane chokes him.

Darkbane: Your choice.

Eli: Doesn't look like we have a choice.

Giving no other choice, they've surrender and were escorted to the leader of the Darkbane while YN hands were tied due to his resisting before. They then walk through the hallway where theres multiple Darkbane.

Kord: Sort of makes you miss the ghouls.

YN: You and me both.

When they meet the leader, they notice something above its thrown.

Trixie: (Whispers.) Eli look!

Eli: (Whispers.) I see it. That's the sun.

Brimstone: We don't have many opportunities to accept visitors here. Your guardian slugs see to that.

YN: Well can't say I blame them since you boys don't look nice.

Eli: (Glares.) Who are you?

Brimstone: I am Brimstone, high commander of the Darkbane. Why are you here midlanders.

YN: Oh you know, someone was banging the door and we answered it. Turns out your pals ruin our bedtime.

Eli: You've been trying to knock down our forcefield, we came to stop you!

Brimstone: (Evil grin.) And how is that going?

Eli: Could be better. But right now, an army of guardian slugs is on their way to defend the passage. They may already be there.

Just as he approaches, the Darkbanes stops him with their staff.

Brimstone: Then so be it. Even if our behemoth fails, we have other ways to reach the realm above. And when slugterra is laid waste, our oath continues to take back what's ours. We will have everything!

Eli: We will stop you. All of slugterra will!

Brimstone: Strong words, coming from a boy. Your forcefield is at the breaking point. A legion of Darkbane are preparing for the final assault. There is very little you can do...expect watch-

Suddenly YN charges and jumps before giving brimstone a headbutt directly to his face since his hands are tied up.

YN: All I see is that I kick your butt without even my hands!

One of the Darkbane put him on his knees and held him while the others point their spear at him until Brimstone stops them as he wipe his blood away from his face and grins.

Brimstone: Impressive, not many has the strength to even wound a Darkbne. But it will not be enough.

Just then one of the Darkbane approaches to the leader and whispered.

Brimstone: Ah, that explain things. He says he knows you two, he says you are a Shane and a LN. It makes you useful to me and that young Shane just saved all your lives.

LN however, will perhaps be entertaining like other LNs. Find them a room, the can keep their worthless slugs. But separate the LN to a different room. It will remind our guests how helpless they really are here as the LN.

YN: LN? What are you talking about-

He was then interrupted by one of the Darkbane pushing him, forcing him to be separated from his friends while they head to a different direction.

YN POV

Just when I got separated, they toss me in a different cage. But got back up and look to see its all clear.

YN: OK Frost, let's do this.

Frost jumps out of my backpack and freezes the cuffs to successfully free my hands before I try to break out of the cage. But suddenly I hear a strange voice.

???: Frost? Is that actually you? I haven't heard her name ever since.

I quickly turn around only to see a stranger sitting down while hiding in the shadow.

YN: Who are you? Are you a friend or a foe?

???: If I was your foe, I wouldn't be here in a first place. Plus your still breathing.

YN: Point taken. But that still doesn't mean I can trust you.

???: Maybe your slug friend can, right Frost?

Frost jumps off of my shoulder and she sounded very surprised and immediately smiles excitedly.

YN: Frost, you know him?

???: I know her too as I know you YN LN.

YN: Who are you?

The stranger stands up and walks out of the shadow. As soon as he was out of shadow to reveal his face, my eyes widen and it took my breath away to see someone I thought I would never see.

YN: Dad!?

DN: Hey there cowboy. Been a long time.

YN: I....I don't understand. Why and how are you here!?

DN: I know its hard to believe it and unforgiving. But there's a good reason.

YN: A good reason? A good reason!? 2 years you've been gone and now you're just here in the cage in deep cavern!?

I punch the wall out of anger before taking a breath.

DN: I know....but I did what I needed to do. I needed to protect the only home we have.

YN: Yeah, but why you? Why couldn't it be the shadow clan?

DN: Its hard to understand. But you've met them right?

YN: The shadow clan? What about them?

DN: Have they ever mentioned anything about our family?

YN: (Deep sigh.) Yeah....The same as all LN's do in the time of unbalanced....so this is what we do then?

DN: Only in a time of unbalanced. But our family have a very long history in slugterra.

This caught me interest. Since the day my dad left, I wanted to know where he went and why. So I decided to sit down and listen what he has to say.

DN: A long time ago in ancient times the Darkbanes attacked our village and the LN family fought back since the Darkbane never knew our true strength. When the shadow clan learn about our tribe facing them. They made an agreement that we'd fight and push them back to the deep cavern in exchange to burn all the records of our family existence.

I had to uphold it and enter the deep cavern with the help of the shadow clan. Since that day, I've been trying to stop them as long as I could but more important since that day, I miss you and your mom every moment I've had.

YN: (Sigh.)...least you had a robotic arm. Red?

DN: With a little modifications.

I don't know whether I should be mad or not. Its hard to believe that my whole family have been doing this ever since. I sat next to him and take a deep breath to clear my head.

YN: So this whole time, we've been just doing the shadow clan favor?

DN: No, we're doing slugterra a favor without anyone knowing.

YN: Makes sense since its our only home....you do know mom's not gonna let this slide when she finds out.

DN: Well by the looks of it, I got a lot of explanation. Least you don't have to go through that for a while.

YN: Speaking of which, I uh....have a girlfriend.

DN: Do you now? Thats a good thing. Who is she by the way?

YN: Dana Por.

DN: Tom Pors daughter? Well I'll be dam! Bet he'd be spying on you while you two were on a date. (Sigh.) Though I wish he was still around. Thanks to Will Shane.

YN: We uh...had a small fight, but we let bye gone be bye gone.

DN: Nice to know my son have friends and a girlfriend. She's a good one.

YN: her eyes and smiles says everything.

DN: Then why don't you marry her?

YN: Dad!?

DN: What? Your mom and I made a promise that we'd be married when I was your age. It ain't easy to say no with a woman like her.

YN: Yeah...too bad I won't be able to see her now that we're stuck here...(Smirk.) But good thing we have a way out. Spike?

Spike appears and hands me two spikes. Giving me a chance to pick the lock. Fortunately the lock is similar as slugterra as I successfully unlock the door.

DN: Not bad. You train your slugs good.

YN: Had a lot of practice thanks to Dana.

DN: Wait what?

YN: Its a long story, one will have to wait. That behemoth is trying to destroy the gate as we know it.

DN: I know.

YN: You do?

DN: I tried to stop it and keep it away for as long as I can but I was overwhelmed.

Suddenly we hear the horn and we make our way out. Once we were out and away from the Darkbane fortress, we see legion of Darkbane are marching towards the gate.

YN: This isn't good.

DN: We need to stop them and protect the gate!

YN: How? We can't use slugs here.

Suddenly we saw the ice appeared and block the legion from going further. It looked like frostcrawler doing. But then I saw my friends are there and fighting their way back. But to my shock, I see them using ghouls.

DN: Friends of yours?

YN: Yeah, but later. Come on.

3rd POV

The Shane gang clear out the Darkbanes and fire the ghouls at the behemoth. But even with the ghouls, it wasn't enough to stop it.

Trixie: Its just too big, our ghouls are like gnats!

Kord: So how are we gonna bring that down!?

Eli: If we can't take it down, aim for the rider!

Suddenly they were interrupted by a lava orb thrown by Brimstone

Brimstone: You've made use of our dark water I see, its becoming very popular.

Eli fires his rammstone ghoul at him, but Brimstone just catches it and throws it away.

Brimstone: Oh you're not the first kind to come here, I've dealt with humans before. Even the Shane's and LN's. Its a shame your LN friend isn't here to help you.

???: Someone called our name!?

Out of nowhere, YN attacks from above and landed a hard drop kick directly to Brimstone chestD

Others were about to attack but was stopped by DN taking down one by one.

Trixie: No way, is that!?

Kord: DN LN!?

Eli: YN's dad?

Brimstone: YOU!?

DN: What? You guys been too noisy I couldn't sleep.

Brimstone: Grrr strike again, the forcefield is failing! The guardian slugs are weak!

With it, the behemoth hits the gate one last time and it destroyed the forcefield.

DN: Oh no...

Brimstone: At last!

DN: Everyone, to the crossing! We'll have to hold them off from the other side!

Everyone does what he said and got back to slugterra. However, the shadow clan notice their slugs except for YNs are ghouls as it got him angry.

Eli: I know, we'll fix them.

YN: I don't know why you did it but you better when this is over.

Kord: Guys?

They look and see Brimstone is riding on the behemoth and breaks the ice wall for the legion to come through and charge. Behind everything, Doc notice the guardian slugs are down and without hesitation, he quickly heals one of them. The shadow clan notice it and sees that Doc successfully heals one of the guardian slugs.

DN: We need to stop that behemoth!

YN: OK, I have an idea but its crazy.

Eli: At this point we could sure use it right now!

YN: Just take out the rider and I'll do the rest!

Eli fired Burpy ghoul at the rider before YN ran and jumps on the behemoth.

YN: (Grin.) Like riding on a bull! Yeeeehaaaaaw!

YN charges directly towards the Darkbane legion.

Brimstone: Attack!

The throw lava at the behemoth but YN quickly got off before any of it could hit him as the behemoth successfully took down the legion except for Brimstone who jump back on the creature. While this was happening, the shadow clan picks up Doc and uses its powers to heal the guardian slugs while the Shane gang notice it.

Eli: The shields going back up!

Trixie: Look, its Doc!

DN: YN, hurry before you're sealed in!

At the last moment, he quickly jumps through before the behemoth's head was through but the gate was too small for the rest of the body to fit.

At that moment, the gate sealed back killing the creature as it anger Brimstone for their escape.

Brimstone: We'll meet soon enough...

Back with the Shane gang, Eli cure their slugs back to normal with a help of Doc and Mercy.

Eli: You really save the day this time Doc.

Shadow clan: You have done a terrible thing. Corrupting the essence of these slugs. Almost unforgivable...

DN: They had no choice, the slugs couldn't transform in their normal state.

Eli: If it makes you feel any better, it was their idea.

Eli hold up Burpy and doc. After that, the shadow clan speaks up with caught them curiously.

YN: That's unexpected.

Trixie: What is it?

Eli: He says that earlier when he told us our slugs weren't ready to be guardians, he missed one.

Eli reveal its Doc who's the new guardian slug.

DN: Fitting since he saved the guardians.

Shadow clan: (Picks up Doc.) There is no greater honor for a slug than to serve as a guardian.

Eli: (Smiles.) We're proud of you Doc, and we'll see you again soon. I promise.

The shadow clan place Doc in one of the guardian spot for him as the tattoos appear around him as well as his symbol above his head.

YN: I'm glad your back too dad.

Kord: (Smiles.) Its a great honor to meet you DN LN!

DN: Nah its alright, DN would be better no need to get honory up. I'm just glad to be back.

Trixie: So your gonna help us stop Dr Blakk?

DN: Maybe later, I have something important to do with the shadow clan. But right now I'd like to get some rest and I'm proud that my son have friends like you to watch out for each other.

YN: Thanks dad. Its good to see you too.

Eli: DN, I have to know, does my dad...?

DN: To be honest, don't really know. But I do know this, he'd be proud of you fighting back for slugterra.

Eli: Thank you DN. Let's go home guys.

The Shane gang then leave as DN looks back at the shadow clan where they both nod in agreement. They have what they needed to know, they only hope nothing else went through the gate.